1. Field of the Invention
The invention relates generally to helix-actuated adjustable open end wrenches and, more particularly, but not by way of limitation, it relates to improved manufacture and construction of such wrenches to enable ready manufacture and improved operation.
2. Description of the Prior Art
The prior art includes numerous types of helix-actuated open end adjustable wrenches, some of which are quite old in the art. Some of the early approaches to such wrench construction may best be characterized by the U.S. Pat. No. 2,795,987 in the name of Schlote; but some other more recent U.S. Pats. relating to the similar type of wrench are U.S. Pat. No. 3,541,899 to Tanner, U.S. Pat. No. 3,555,939 to Halls, U.S. Pat. No. 3,640,159 to Halls et. al., and U.S. Pat. No. 3,673,896 in the name of Vardaman. While inspection of the cited prior art will show that the type of wrench in question has received wide attention and much industry of development, it becomes apparent that there are many inherent difficulties and problems to be overcome in manufacturing a helix-actuated open end adjustable wrench of proper design characteristics and operational reliability.